Advanced aromatic epoxy resins are well known for their extremely useful combination of properties such as, for example, flexibility, adhesion, resistance to corrosion, chemical and solvent resistance, and the like. Unfortunately, they also have some well known disadvantages such as, for example, sensitivity to ultraviolet light, relatively high viscosities, limited formability, and the like.
Epoxy phosphate esters have been prepared by various processes for water thinnable coating formulations. It has been unexpectedly discovered that these phosphate esters, when employed in non-aqueous formulations, give outstanding barrier properties to the resulting coatings when compared to the base resins from which they are derived. Epoxy resin phosphate esters and methylol containing curing agents can be formulated to give bake coatings with exceptional improvements in flexibility, adhesion and formability with retention of traditional epoxy protection.